From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E24CBC0650F for ; Mon, 5 Aug 2019 09:22:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA05420B1F for ; Mon, 5 Aug 2019 09:22:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728063AbfHEJWC (ORCPT ); Mon, 5 Aug 2019 05:22:02 -0400 Received: from mx2.suse.de ([195.135.220.15]:44262 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728023AbfHEJWB (ORCPT ); Mon, 5 Aug 2019 05:22:01 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id D4025AFF0; Mon, 5 Aug 2019 09:21:59 +0000 (UTC) Date: Mon, 05 Aug 2019 11:22:03 +0200 Message-ID: From: Takashi Iwai To: Christoph Hellwig Cc: iommu@lists.linux-foundation.org, Marek Szyprowski , Takashi Iwai , Robin Murphy , Michal Simek , linux-arm-kernel@lists.infradead.org, linux-m68k@lists.linux-m68k.org, linux-parisc@vger.kernel.org, linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/7] ALSA: pcm: use dma_can_mmap() to check if a device supports dma_mmap_* In-Reply-To: <20190805091159.7826-5-hch@lst.de> References: <20190805091159.7826-1-hch@lst.de> <20190805091159.7826-5-hch@lst.de> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 05 Aug 2019 11:11:56 +0200, Christoph Hellwig wrote: > > Replace the local hack with the dma_can_mmap helper to check if > a given device supports mapping DMA allocations to userspace. > > Signed-off-by: Christoph Hellwig > --- > sound/core/pcm_native.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c > index 703857aab00f..81c82c3ee8a2 100644 > --- a/sound/core/pcm_native.c > +++ b/sound/core/pcm_native.c > @@ -220,12 +220,11 @@ static bool hw_support_mmap(struct snd_pcm_substream *substream) > { > if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_MMAP)) > return false; > - /* architecture supports dma_mmap_coherent()? */ > -#if defined(CONFIG_ARCH_NO_COHERENT_DMA_MMAP) || !defined(CONFIG_HAS_DMA) > + if (!dma_can_mmap(substream->dma_buffer.dev.dev)) > + return false; > if (!substream->ops->mmap && > substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV) > return false; > -#endif This won't work as expected, unfortunately. It's a bit tricky check, since the driver may have its own mmap implementation via substream->ops->mmap, and the dma_buffer.dev.dev might point to another object depending on the dma_buffer.dev.type. So please replace with something like below: --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -221,11 +221,10 @@ static bool hw_support_mmap(struct snd_pcm_substream *substream) if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_MMAP)) return false; /* architecture supports dma_mmap_coherent()? */ -#if defined(CONFIG_ARCH_NO_COHERENT_DMA_MMAP) || !defined(CONFIG_HAS_DMA) if (!substream->ops->mmap && - substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV) + substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV && + !dma_can_mmap(substream->dma_buffer.dev.dev)) return false; -#endif return true; } Thanks! Takashi